Time delay devices



July 8, 1958 G. COLOMBO EIAL 2,842,642

TIME DELAY DEVICES Filed June 15, 1956 s Sheets-Sheefll IN VEN TORS y 1953 G. COLOMBO ET AL 2,842,642

TIME DELAY DEVICES Filed June 13, 1956 3 Sheets-Sheet 2 INVENTORS 721 July s, 1958 Filed June 13, 1956 G. COLOMBO ETAL 2,842,642

TIME DELAY DEVICES 3 Sheets-Sheet 3 FIG.6

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U43, i ATTORNEY United States Patent TIME DELAY DEVICES George Colombo, East Rockaway, and Boris Orlov, Brooklyn, N. Y., assignors, by mesne assignments, to Hoda Corporation, Great Neck, N. Y., a corporation of New York Application June 13, 1956, Serial No. 591,239

6 Claims. (Cl. 200-122) This invention relates to time delay devices and, more particularly, to a novel time delay device comprising sequentially activated thermostatically operated switching means operative to efi'ect a predetermined function a preset time interval after a control circuit is closed.

Time delay devices are employed in many types of switching apparatus. A typical application is in a signal cancelling arrangement for an automotive vehicle turn signaling system. In this application, the time delay cycle is initiated when the selector lever is moved to signal a turn. After a predetermined interval, the time delay device or means releases a latch or the like whereupon suitable biasing means move the selector lever to a neutral position.

However, the time delay devices hitherto used for this purpose have either been bulky and complicated or else incapable of providing an effectively long time delay.

Consequently, there is a demand for a compact time delay device having a sufiiciently long time delay action to render it adaptable for use in such an automotive vehicle signal system.

In accordance with the present invention, a time delay device is provided which is not only compact and simple but also has the requisite time delay characteristics for use in automotive vehicle signal systems. More particularly, the time delay device of the present invention com prises an electrically conductive metal bracket on which is mounted a pair of snap action, electrically conductive metal vanes normally deformed to a stressed condition by pull ribbons secured at their ends to spaced points on the vanes.

The vanes are preferably of the type described and claimed in U. S. Patent No. 2,706,226, and comprise preferably square thin metal vanes having longitudinally spaced relatively elongated deformations extending along one diagonal to give an initial bend or set to the vane. The vane is bent about the other diagonal to a stress-deformed position by the aforementioned pull member secured at its ends to the vane at opposite ends of the first diagonal. When vanes of this type are fixedly mounted at a certain point spaced to one side of the first diagonal, the portion of the vane extending across the first diagonal will pivot or snap about the fixed mounting point, with a considerable amplitude of movement.

In the subject time delay device, each pull ribbon or wire has a high resistance insulated winding thereon and, in the case of one vane, one end of the wire is connected to the pull member. One terminal of a battery or other source of potential is connected to the mounting bracket. The bracket carries, in insulated relation thereto, a. conductive metal band connected to one terminal of the heating winding of the second vane. The metal band also carries a contact engageable by a contact on the free or movable portion of the first vane, the contacts being engaged when the first vane snaps to its normal bent position upon heating and expansion of its pull element. A similar contact on the tree portion of the second vane is engageable with a fixed contact when the second vane snaps to its normal bent position upon heating and expansion of its pull member.

This fixed contact and the other ends of the two heating windings are commonly connected through a switch to one terminal of a relay coil or other controlled device, the other relay coil terminal being grounded.

The time delay device operates as follows:

When the switch is closed, current flows from the battery into the bracket and thence into the first vane and, through its pull member, to the high resistance heating winding thereof. After a predetermined heating interval, the pull member expands sufficiently for the first vane to snap to its normal bent position, engaging the contact on the first vane with the contact on the bracket supported metal band. This completes an energizing circuit for the heating winding of the second vane, in parallel with the still energized circuit for the heating winding of the first vane. After a second pre-set heating interval, the second pull member expands sufficiently for the second vane to snap to its normal bent position and engage its contact" with the fixed contact.

Current now flows directly from the battery through the bracket, the second vane, the fixed contact and the relay coil. The high resistance vane heating circuits are shunted, and the current flow in the relay coil, previously limited by the high resistance windings, is now sufiicient to operate the relay to perform a control function.

In the case of an automotive vehicle signaling system, the switch is closed by movement of the selector lever to signal a turn. When the relay coil is effectively energized, it releases a latch holding the lever in an operated position, and the lever, biased back to its neutral position, opens the switch.

For an understanding of the invention principles, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing. In the drawing:

Fig. 1 is a plan view of a snap action vane used in the time delay device;

Fig. 2 is a top plan view of the device;

Figs. 3 and 4 are opposite side elevation views of the device;

Fig. 5 is an end elevation view of the device;

Fig. 6 is a schematic wiring diagram of a turn signaling system embodying the invention; and

Fig. 7 is a side elevation view of a vane illustrating an alternative pull member arrangement.

Referring to Fig. 1 of the drawing the time delay device employs thermostatic circuit closers incorporating snap action vanes preferably of the type shown and described in said patent. Vane 10 is given an initial set or bend by deformations 15 extending along diagonal 11, 12, the deformations being interrupted at the vane center. The vane is stress-deformed along the other diagonal 13, 14 by attaching a heat expansible pull member 16 thereto, member 16 being secured, in the cold and contracted condition, to corners 11, 12.

When member 16 expands due to heating thereof, vane 10 snaps to its initial bent position about line 11, 12. If vane 10 is fixedly mounted at a point to one side of the diagonal 11, 12, the part of vane 10 on the other side of the diagonal will have a considerable amplitude of movement during snapping of the vane. This vane movement may be utilized to effect opening and closing of an electrical circuit, and is utilized in the present invention.

With reference to Figs. 2-5, the time delay device 20 comprises a dielectric base 21 having terminals 22, 23 projecting therefrom, these terminals being in the form of contact prongs for insertion in a socket or the like. Contact 22 is electrically connected to an electrically conduc- 3 tive metal bracket or support 25 having upper branches 26, 27 each having a vane or 10 electrically and mechanically secured thereto. For a purpose to be described, a band 30 of conductive metal is mounted in insulated relation on bracket 25 and carries a contact 31. 7

An insulated high resistance heating winding 35 is wound on pull member 16 of vane 10 and has one end electrically and mechanically connected to the pull member. The other end of winding 35 is electrically connected to terminal 23. The free portion of vane 10 carries a contact 32 engageable, upon snapping of vane 10 to its initially bent position, with contact 31 on band 30.

Pull member 16' of vane 10' has an insulated high resistance heating winding 35 wound thereon. Winding 35 has one end connected to band 30 and its other end connected to terminal 23. The portion of vane 10' carries a contact 36 engageable, upon snapping of the vane to its preset position, with a fixed contact 37 electrically connected to terminal 23.

The operation of the time delay device will be best understood from Fig. 6 which illustrates device 2%) as incorporated in an automotive vehicle turn signaling system. The turn signal switch 40 comprises a dielectric mounting member or base 41 upon which is oscillatably mounted a dielectric disk 42. A selector lever 43 is secured to disk 42. Contact 44 on base 41 is connected to terminal 46 of flasher 45, the flasher having a terminal 47 connected to pilot or indicator lamp PL and a terminal 48 connected to post 49 of grounded battery 50. a

A contact 51 on base 41 is connected to left front signal lamp LF and left rear signal lamp LR, and a contact 52 on the base is connected to right front signal lamp RF and right rear signal lamp RR. vContact 53 on base 41 is connected to terminal 23 of time delay device 2t Disk 42 carries a first two-arm circuit closer 54 arranged to selectively interconnect contact 44 to either of the contacts 51 or 52. A second two-arm circuit closer 56 is arranged to engage contact 53 in either operated position of switch 40, and circuit closer 56 is connected by a flexible conductor 57 to one terminal of a relay or solenoid coil 55, the other coil terminal being grounded. A paramagnetic spring latch 60 on base 41has a latch end 61 engageable in either of a pair of notches 62, 62' in disk 42 depending upon the direction in which the disk is operated. A magnetic core 58 associated with coil 55 is arranged to magnetically retract latch 69 from notches 62 or 62' whenever coil 55 is fully energized.

Suitable biasing means, schematically indicated as springs 63, bias disk 42 and handle 43 to the illustrated neutral position.

The arrangement operates as follows. Assuming a left turn is to be signalled, handle 43 is moved counterclockwise and latch end 61 snaps into recess 62. Circuit closer 54 interconnects contacts 44 and 51 so that lamps LF and LR are connected to flasher 45. Both these' lamps and pilot lamp PL are flashed.

At the same time, circuit closer 56 is engaged with contact 53. Current now flows from post 49 of battery through terminal 22, bracket 25, vane 10, pull member 16, high resistance heating winding 35, terminal 23, contact 53, circuit closer 56, conductor 57, coil 55, and ground. Due to the high resistance of winding 35, the current flow is insuflicient to fully energize winding 55. As winding 35 beats pull member 16, the latter expands and, after an interval, vane 10 snaps to its normal position, engaging contact 32 with contact 31. This closes a second circuit, in parallel with that just described, as follows: bracket 25, vane 10, contacts 32, 31, band 30, winding 35', terminal 23, and thence as previously stated. Coil is still not fully energized, .due to the high resistance of windings 35 and 35'. i

As winding 35' heats pull member 16, the latter expands and, after a pre-set time interval, vane 10 snaps to its normal bent position, engaging contacts 36 and 37. This completes a circuit shunting windings 35 and 35, as follows: bracket 25, vane 10, contacts 36, 37, terminal 23, contact 53, circuit closer 56, conductor 57, winding 55 and ground. Winding 55 is now fully energized so that core 58 retracts latch 60 from notch 62. Disk 42 is biased back to the neutral position, opening all the circuits, and pull members 16 and 16 contract to stress-deform vanes 10 and 10' due, first, to the shunting of windings'35, 35, and later to the opening of the circuits.

The desired time delay can be pre-set by proper selection of the heating windings 35, 35' or by adjusting their heating eilect on pull members 16, 16. Fig. 7 illustrates an arrangement wherein theheating rate of the pull member is decreased to increase the time delay. In this figure, a conductive metal strip 65 is secured at each end to pull member 16" of vane 10", and winding 35" is carried by ribbon 65. The winding first heats ribbon 65 and the heat of the ribbon is conducted into pull member 16". Due to the indirect heating of the pull member, a longer time interval is required for the pull member to expand sufficiently to allow snapping of vane 10". Other means may be used to increase the heating interval of the pull member, such as heavier insulation on the heating windings.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

We claim: I

l. A time delay device for initially restricting the flow of current between a pair of terminals, said device comprising, in combination, a base having first and second terminals for connection across a source of electric potential; a first normally open thermostatically operated switch mounted on said base; a first high resistance heating circuit for closing said first switch, said first circuit being connected between said terminals for energization when a potential is applied across said terminals; a second normally open thermostatically operated switch mounted on said base; and a second high resistance heating circuit for closing said second switch, said second circuit being connected between said terminals in series with said first switch for energization when a potential is applied across said terminals, and said first switch is closed; said second switch being connected between said terminals and efiective when closed, to shunt said heating circuits; whereby, when said terminals are connected across a source of potential, said first circuit will be energized to close said first switch after a first pre-set time interval to energize said second circuit to close said second switch after a second pre-set time interval to shunt said heating circuits to reduce the electrical resistance between said terminals to a negligible value to permit substantially unrestricted flow of current between said terminals.

2. A time delay device for initially restricting the flow of current between a pair of terminals, said device comprising, in combination, a base having first and second terminals for connection across a source of electric potential; a first normally open switch mounted on said base; first thermostatic electric operating means effective, after a first pre-set time interval of energization, to close said first switch, said first operating means being con nected between said terminals for energization when a potential is applied across said terminals; a second normally open switch mounted on said base; and second thermostatic electric operating means effective, after a second pre-set time interval of energization, to close said second switch, said second operating means being connected between said terminals in series with said first switch for energization when a potential is, applied across said terminals and said first switch is closed; said second switch being connected between said terminals and efiective when closed, to shunt said thermostatic operating means; whereby, when said terminals are connected across a source of potential, said first operating means will be energized to close said first switch after such first preset time interval to energize said second operating means to close said second switch after such second pre-set time interval to shunt said operating means to reduce the electrical resistance between said terminals to a negligible value to permit substantially unrestricted flow of current between said terminals.

3. A time delay device for initially restricting the flow of current between a pair of terminals, said device comprising, in combination, a base having first and second terminals for connection across a source of electric potential; a first normally open thermostatically operated switch mounted on said base; a first high resistance heating winding for the operator of said first switch effective, When energized, to heat its associated switch operator to close said first switch; said first winding being connected between said terminals; a second normally open thermostatically operated switch mounted on said base; and a second high resistance heating winding for the operator of said second switch effective, when energized to heat its associated switch operator to close said second switch; said second winding being connected between said terminals in series with said first switch; said second switch being connected between said terminals and efiective when closed, to shunt said windings; whereby, when said terminals are connected across a source of potential, said first winding will be energized to close said first switch after a first pre-set time interval to energized said second winding to close said second switch after a second preset time interval to shunt said windings to reduce the electrical resistance between said terminals to a negligible value to permit substantially unrestricted flow of current between said terminals.

4. A time delay device for initially restricting the flow of current between a pair of terminals, said device comprising, in combination, a dielectric base having first and second terminals for connection across a source of electric potential; a conductive metal bracket mounted on said base in electrical connection with said first terminal; first and second conductive metal snap action vanes each secured at a fixed point to said bracket in electrical connection therewith; first and second heat expansible conductive pull members, each secured at its ends to a vane '6 l in electrical connection therewith, and normally holding the vane in stress-deformed condition; each vane upon expansion of its pull member, snapping to a normal position about its fixed mounting point; a first contact electrically and mechanically connected to the tree portion of said first vane; a second contact electrically and mechanically connected to the free portion of said second vane; a third contact mounted in insulated relation on said bracket and engageable by said first contact upon snapping of said first vane; a fourth contact electrically connected to said second terminal and engageable by said second contact upon snapping of said second vane; a first high resistance heating winding for said first pull member electrically connected between said first pull member and said second terminal; and a second high resistance heating winding for said second pull member electrically connected between said third contact and said second terminal; whereby, when said terminals are connected across a source of potential, said first winding will be energized to snap said first vane after a first pre-set time interval to engage said first and third contacts to energize said second winding to snap said second vane after a second pre-set time interval to engage said second and fourth contacts to shunt said windings to reduce the electrical resistance between said terminals to a negligible value to permit substantially unrestricted flow of current between said terminals.

5. A time delay device as claimed in claim 4 in which said heating windings comprise insulated high resistance wire wound on said pull members.

6. A time delay device as claimed in claim 4 in which each pull member comprises a pull ribbon secured at each end to a vane, and a conductive metal strip extending parallel to and secured at each end to said ribbon, the associated heating winding being carried on said strip.

References Cited in the file of this patent UNITED STATES PATENTS 1,700,661 Appelberg Jan. 29, 1929 2,040,923 Doane May 19, 1936 2,095,579 Werner Oct. 12, 1937 2,441,979 Schmidinger May 25, 1948 2,673,937 Hollins Mar. 30, 1954 2,674,730 Klebanofi et a1 Apr. 6, 1954 2,704,360 Werstein Mar. 15, 1955 2,717,331 Hollins Sept. 6, 1955 2,737,553 Welsh Mar. 6, 1956 2,757,315 Hollins July 31, 1956 

